Heretofore, an alumina substrate prepared by sintering an alumina powder has been widely used as an electronic circuit board.
For the above alumina substrate, since the alumina powder has a high sintering temperature of about 1,600° C., only a high melting point metal such as tungsten (melting point: 3,400° C.) or molybdenum (melting point: 2,620° C.) can be used as a material of an electrode which is calcined simultaneously with preparation of the alumina substrate. Accordingly, a non-high melting point metal such as silver (melting point: 962° C.) having a small resistivity but having a melting point of at most 1,600° C. can not be used as a material of the above electrode, such being problematic.
In recent years, a material for an electronic circuit board with which an electronic circuit board can be prepared by calcination at a temperature of at most 900° C., as the alternative to the above alumina powder, has been required.
It is an object of the present invention to overcome the above problems, and to provide a glass ceramic composition suitable for preparation of an electronic circuit board.